CollectionView

A scrollable list that displays data items in cells, one per row. Cells are created on demand and filled with widgets in the initializeCell callback.
Includes Widget

Methods

insert(items)

Parameters:

items: any[]

Inserts the given items into this view. Items are added at the end. This operation will modify the items property.

insert(items, index)

Parameters:

items: any[]

index: number, the position to insert the items at. If a negative index is given, it is interpreted as relative to the end. If the given index is greater than the item count, new items will be appended at the end.

Inserts the given items into this view at the given index. This operation will modify the items property.

refresh()

Parameters:

Triggers a refresh of all visible items. This will issue change:item events on the corresponding cells.

refresh(index)

Parameters:

index: number, the index of the item that was changed.

Triggers a refresh of the item with the given index. If the item is scrolled into view, an change:item event will be issued on the corresponding cell.

remove(index)

Parameters:

index: number, the index of the item to remove. If this is negative, it is interpreted as relative to the end.

Removes the item at the given index from this view. This operation will modify the items property.

remove(index, count)

Parameters:

index: number, the index of the first item to remove. If this is negative, it is interpreted as relative to the end.

count: number, the number of items to remove.

Removes count items beginning with the given index from this view. This operation will modify the items property.

reveal(index)

Parameters:

index: number, the index of the item to reveal. If this is negative, it is interpreted as relative to the end

Scrolls the item with the given index into view.

Properties

cellType

Type: *string

Function*

The name of the cell type to use for a given item. This name will be passed to the initializeCell and itemHeight functions. Cells will be reused only by items that require the same cell type. If set to a function, this function will be called for every item, providing the item as a parameter, and must return a name for the cell type to use for the given item.

columnCount

Type: number, default: 1

The number of columns to display in the collection view. If set to a value n > 1, each row will contain n items. The available space will be equally distributed between columns.

firstVisibleIndex

Type: number

The first item that is currently visible on screen. This property is read-only.

initializeCell

Type: Function

A callback used to initialize a collection cell by attaching widget and change:item listener. Cells are created by the framework and recycled on scrolling. This callback receives the cell as the first and the cell type as second parameter.This property can only be set on widget creation. Once set, it cannot be changed anymore.

itemHeight

Type: *number

Function*

The height of a collection cell. If set to a function, this function will be called for every item, providing the item and the cell type as parameters, and must return the item height for the given item.

items

Type: any[]

An array of data items to be displayed by the collection view. For dynamic content, use the methods insert and remove instead of setting this property directly.

lastVisibleIndex

Type: number

The last item that is currently visible on screen. This property is read-only.

refreshEnabled

Type: boolean, default: false

Enables the user to trigger a refresh by using the pull-to-refresh gesture.

refreshIndicator

Type: boolean, default: false

Whether the refresh indicator is currently visible. Will be set to true when a refresh event is triggered. Reset it to false when the refresh is finished.

refreshMessage

Type: string, default: ""

The message text displayed together with the refresh indicator. Currently not supported on Android.

Events

“refresh” (widget)

Parameters:

widget: this

Fired when the user requested a refresh. An event listener should reset the refreshIndicator property when refresh is finished.

“scroll” (widget, event)

Parameters:

widget: this

event: {deltaX: number, deltaY: number}, contains the scroll delta of this scroll event {deltaX: number, deltaY: number}. The value of deltaY will be positive when scrolling up and negative when scrolling down.